Bucket loader

ABSTRACT

A mobile loader having a vertically positionable bucket which can be used in earth working operations and the like and which can lift, transport, and dump a load as well as scrap the earth for levelling thereof. The loader has a hydraulically operated, parallel linkage arrangement for maintaining the bucket level regardless of its vertical position. The mounting linkage for the bucket is also such that the bucket can be moved to a completely dumping position for good clean-out of the bucket, it can be maintained in a level position regardless of its vertical position while at the same time the linkage and its associated hydraulic system permit the bucket to be moved to a lower, scraping position in which it is generally curled inwardly to provide good scraping action. The above described loader also has a quick attachment means for attaching the bucket to the linkage mechanism and by means of which the operator can simply drive the vehicle up to the rear side of the bucket and then manipulate the linkage to attach the bucket.

United States Patent Leverenz Oct. 23, 1973 BUCKET LOADER [57] ABSTRACTJohn LeYel-enz west Bengl Wis?- A mobile loader having a verticallypositionable 7 Assign: gehlcompambwest Bendwis' bucket which can be usedin earth working operations and the like and which can lift, transport,and dump a Filed: 1971 A load as well as scrap the earth for levellingthereof. [21] Appl. No.: 200,898 The loader has a hydraulicallyoperated, parallel linkage arrangement for maintaining the bucket levelregardless of its vertical position. The mounting [52] US. Cl 214/776,214/145, 2l4/DIG. l0 linkage for the bucket is also such that the bucketcan [5 lnt. be o e to a p e e y p g p s i f g [58] Field of Search214/143, l,)7li.7l7O6, cleamout of the bucket it can be maintained in a21 l level position regardless of its vertical position while ReferencesCited at the same time the linkage and its associated hydraulic systempermit the bucket to be moved to UNlTED STATES PATENTS a lower, scrapingposition in which it is generally 3,275,l63 9/1966 Schaeff 214/138 Rcurled inwardly to provide good craping action Primary ExaminerGerald M.Forlenza Assistant Examiner-John Mannix Attorney-James E. Nilles Theabove described loader also has a quick attachment means for attachingthe bucket to the linkage mechanism and by means of which the operatorcan simply drive the vehicle up to the rear side of the bucket and thenmanipulate the linkage to attach the bucket. 7 W p 7 V V 2 Claims, 9Drawing Figures PATENTED Ill)! 2 3 \973 SHEET 3 0F 4 BUCKET LOADER Theloader has a hydraulically operated, parallel linkage arrangement formaintaining the bucket level regardless of its vertical position. Themounting linkage for the bucket is also such that the bucket can bemoved to a completely dumping position for good clean-out of the bucket,it can be maintained in a level position regardless of its verticalposition while at the same time the linkage and its associated hydraulicsystem permit the bucket to be moved to a lower, scraping position inwhich it is generally curled inwardly to provide good scraping action.

The above described loader also has a quick attachment means forattaching the bucket to the linkage mechanism and by means of which theoperator can simply drive the vehicle up to the rear side of the bucketand then manipulate the linkage to attach the bucket.

BACKGROUND OF THE INVENTION The invention pertains to end loading,mobile vehicles having vertically positionable arms at the end of whichthe tiltable bucket is mounted. Various hydraulic systems and linkageshave been proposed for maintaining the bucket level regardless of itsvertical position, assuring good loading carrying capacity of the bucketas well as complete dumping thereof. Heretofore however, it has beendifficult to provide a self-leveling bucket and at the same time insurethat the bucket could be used in a lower, scraping positin andstill'furthermore insure that a good dumping angle of the bucket wasprovided at an elevated position.

One example ofa prior art device is shown in the U.S. Pat. No. 3,237,795issued to Kromer on Mar. 1, 1966, and entitled Means for DetachablySecuring Work Heads to Boom Equipped Power Trucks and the Like.

SUMMARY OF THE INVENTION The present invention provides a mobile loaderhaving a linkage for mounting the vertically positionable bucket, whichlinkage includes a pair of parallel links, the upper link of which isformed by a hydraulic cylinder. Furthermore, the linkage is used incombination with a hydraulic control system that has a by-pass reliefvalve and the arrangement is such that the bucket can be maintainedlevel regardless of its vertical position, and in addition, the bucketcan be curled under when it is in the lowermost posiion, to provide agood ground levelling or scraping position for the bucket. Furthermore,the linkage andhydraulic system provided in the present mobile loader issuch that good load carrying capacity of the bucket is assured, thebucket is selfleveling in the raised position, the bucket has a gooddump angle which assures that the load can be completely cleaned out ofthe bucket, and furthermore the bucket can be positioned in a loweredscraping position without the need for any additional adjusting leversto be manipulated by the operator.

Another aspect of the invention provides a loader of the above typewhich has a quick attachment means between the bucket and the linkageand whereby the operator of the vehicle can simply drive up to the backside of the bucket and manipulate the linkage to make the attachment tothe bucket.

These and other objects and advantages of the present invention willappear hereinafter as this disclosure progresses, reference being had tothe accompanying drawings.

THE DRAWINGS FIG. 1 is a perspective view of a loader made in accordancewith the present invention and showing the bucket in the fully raisedand levelled position;

FIG. 2 is a side elevational view of the loader shown in FIG. 1, butshowing the bucket moved to a raised dumping position in which the loadcan be completely cleaned out of the bucket;

FIG. 3 is a side elevational view of the loader showing the bucket movedto a lower position and in which the bucket has also been moved relativeto the linkage to a scraping position in which the bucket is slightlycurled in under the linkage;

FIG. 4 is a view of the loader showing the linkage in the lowermostposition and the bucket in the load carrying position;

FIG. 5 is a side elevational view of the bucket and showing a portion ofthe linkage in its initial stage of being maneuvered for attachment tothe bucket;

FIG. 6 is a rear view of the bucket with the quick attachment means ofthe linkage attached thereto, certain parts being shown as broken awayor removed for the sake of clarity;

FIG. 7 is a perspective view of the bucket taken generally from the rearleft side thereof and showing a fragment of the attaching means inexploded view;

FIG. 8 is a view similar to FIG. 7 and also showing the quick attachmentmeans for connecting the linkage to the bucket, and showing a fragmentof the linkage;

FIG. 9 is a hydraulic circuit diagram utilized'with the loader andshowing the tilt cylinders, the lift cylinders, and the relief valves.

DESCRIPTION OF A PREFERRED EMBODIMENT The loader provided by the presentinvention includes a main frame 1 having a power source such as aninternal combustion engine 2, four ground engaging wheels 3 which areindependently driven toeffect a steering action for the vehicle. Themain frame includes a pair of rear, generally upwardly extendingportions 6. A suitable hydraulic pump P is carried on the vehicle and isdriven by the internal combustion engine (not shown) in the known mannerso as to be able to supply pressurized fluid to the hydraulic system, tobe described, and as shown in FIG. 9.

A load carrying bucket 10 is bodily shiftable in a vertical direction bya parallel arm linkage arrangement LA, and the bucket includes" the endwalls 12, 14, bottom 16, having a scraping edge 17, an angular rear wall18 and a top wall 20. Two pairs of fixed, transversely spaced, lowerbrackets 21, 22 (FIG. 7) are welded to the rear portion of the bucketand have aligned holes through their free ends. Two pairs of upperbrackets 23, 24 are also welded to the rear end of the bucket attransversely spaced locations, and have open ended, downwardly facingslots 25.

The bracket is quickly attached to the parallel arm linkage LA to bedescribed, by means of a quick attachment means now to be described.This means includes two pairs of parallel plates 30 and 31 which arewelded to a connecting tubular shaft 40. The pair of triangular plates30 are connected to one of the pairs of brackets 21 and the pair ofbrakcets 23. The pair of plates 31 are connected to the other pair ofarms 22 and the other pair of brackets 24. A pin 42 extends through theplates 30 to hold them captive on the brackets 21 while a similar pin 43extends through plates 31 to hold them in pivotal connection with thebrackets 22, when the unit is assembled.

The pairs of plates have tubular bushings 44 welded in their upper endsand which are engaged in the slots 25 of upper brackets 23, as willappear.

The parallel arm linkage is as follows. A pair of large, generallyL-shaped lift arms 50 have an arm portion 51 pivotally attached at 53 tothe upright portion 6 of the main frame. The lift arms 50 each also havea forward and generally downwardly extending portion 52 which arepivotally connected at their free ends, respectively, between theirplates 30 and 31 by means of pins 54 (FIG. The linkage of the presentinvention also includes a pair of top links formed by a pair of doubleacting cylinder assemblies 56, each pivotally connected at 57 to theportion 6 of the frame and then pivotally connected at their other endat 58 to a double plate, motion transmitting strut 59. The strut 59 isalso pivotally connected as at 60 to the arm 50 and thus each of thedouble acting cylinder assemblies 56 and its corresponding arm portion51 are in general parallelism with one another.

The parallel linkage of the present invention also has a pair of links62 which are pivoted at 63 to their struts 59, and the other end of thelinks 62 are pivotally connected by means of a long pin 65 to thetubular plates 30 and 31, as'follows. Arms 62 at their ends have shaftsor bushings 64 (FIG.v 8) extending therethrough and welded therewith toform a good bearing surface for the pairs of brackets 23 and 24, as willappear.

When it is desired to hook the parallel linkage arrangement to thebucket, the cylinder assemblies 56 are extended to move the plates 30and 31 to the position shown in FIG. 5 wherebythe bushings 64 of links62 are located just below the open slots 25 of the brackets 23, 24. Thelinkage is then shifted to raise the bushings 64 into the slots 25, andthe plates 30 and 31 are then rotated so the pins 42 and 43 can beinserted through the aligned apertures in the arms 21 and 22 and thecorresponding plates 30 and 31. This provides a very convenient and easyattachment for the bucket.

A pair of single acting, large hydraulically actuated lift cylinders 60and 61 are provided between their corresponding frame portions 6 andarms 50, intermediate the lengthof the latter. These hydraulic cylinders60 and 61 are actuated to vertically position the bucket.

The fluid pump P is driven from the vehicle engine and provides pressurefluid, through the two conventional four-way valves 66 and 67, to thelift cylinders and also to the tilt cylinders as shown by the circuitdiagram of FIG. 9. The valves 66 and 67 are under the influence of thevehicle operator through their spool shifting levers 66a and 67a,respectively.

A relief valve 68 is located in fluid line 69 and is set to crack at apressure of for example 700 p.s.i., as determined by the loadrequirements of the vehicle. Another relief valve 70 is located inseries with valve 68 and is set to ,open at a higher pressure than valve68.

When the linkage mechanism is in the position shown in FIG. 3, theplates 30 and 31 abut against a stop 73 welded to the load arms. Thiskeeps the bucket in that particular relationship to the load arms sothat when the arms are raised as shown in FIG. 2, the bucket maintains agood dump angle. Ordinarily, due to the self-leveling feature of thelinkage arrangement, the bucket would tend to keep curling under thearms when the load arm was raised. However, with the relief valve 68 asdisclosed in FIG. 9, the mechanical stop 73 becomes the limit ofmovement of the bucket relative to the load arm. This causes the reliefvalve 68 to permit the pressure fluid to bypass from one end of the tiltcylinder 56 to the other end of those cylinders via line 69, ashydraulic line 76 connects the rod ends of the cylinders 56 togetherwhile fluid line 77 connects the head ends of the tilt cylinders 56together. Thus, the bypass valve 68 prevents cavitation, and the balanceof the fluid pressure (due to the difference in area between oppositeends of the tilt cylinders 56) then passes through the high value reliefvalve to the sump S.

The present invention thus gives an improved dumped position shown inFIG. 2. The curled back bucket position at ground level (FIG. 3) allowsfor the use of the hydraulic system and bucket for additional traction,either forward or reverse, where unit wheels could not providesufficient traction, for example when the unit is buried in mud andresting on the belly pan of the vehicle.

In addition, when the bucket is then lowered from the FIG. 2 position,the bucket assumes a lowered, scraping position as shown in FIG. 3without any additional adjustment being required on the part of theoperator. It is only necessary for the operator toprovide asmall-adjustment of the actuating tilt lever 67a to finally position thebucket. As a result, the bucket assumes a scraping position in a rapidmanner.

The relief valve provided in the hydraulic circuit 0 FIG. 9 for the tiltcylinders 56 permit the cylinders 56 to contract while the bucket iscurled back under the arms and is being raised. The present hydraulicsystem automatically protects itself while affording the above mentionedadvantages.

I claim:

1. A self-propelled end loader vehicle having a frame, and also having apower source, a fluid pump driven by said power source, and groundengaging means for supporting and propelling said frame, an earthengaging bucket having upper and lower attaching brackets, a parallellinkage assembly for connecting said bucket to said frame for verticallypositioning and tiling said bucket, said linkage assembly comprising,lift arms having an arm portion pivotally connected at one end to saidframe and having a generally-donwwardly extending portion at the otherend, an actuating member pivotally connected to said lift armsintermediate the length thereof, double acting fluid tilt cylinder meansarranged in general parallelism with said arm portion and pivotallyconnected at one end to said frame and at the other end to saidactuating member for swinging the latter,link means pivotally connectedat one end to said actuating means; said double acting fluid tiltcylinder means being longer than said link means, quick attachment meanspivotally connected to said link means and to said lift arm downwardlyextending portions, said quick attachment means also pivotally attachedto said bucket brackets, said upper attaching bucket brackets having anopen slot connection with said quick attachment means, and lift cylindermeans connected between said vehicle frame and said parallel linkassembly for vertically positioning the latter; a fluid control circuitincluding said tilt cylinder means and said lift cylinder means, saidtilt cylinder means including a pair of cylinder and piston units, firstconduit means connecting the rod end of said cylinders in fluidcommunication with one another, second conduit means connecting the headend of said cylinders in fluid communication with one another, a controlvalve between said first conduit means and said second conduit means forcausing selective pressurization of said rod ends and head ends of saidcylinders to cause actuation of said tilt cylinder means to thereby tiltsaid bucket through said actuating member and said link means, and afluid pressure relief valve in said control circuit and in communicationwith said second circuit mounting of said attachment means in saidslots.

1. A self-propelled end loader vehicle having a frame, and also having apower source, a fluid pump driven by said power source, and groundengaging means for supporting and propelling said frame, an earthengaging bucket having upper and lower attaching brackets, a parallellinkage assembly for connecting said bucket to said frame for verticallypositioning and tilting said bucket, said linkage assembly comprising,lift arms having an arm portion pivotally connected at one end to saidframe and having a generally donwwardly extending portion at the otherend, an actuating member pivotally connected to said lift armsintermediate the length thereof, double acting fluid tilt cylinder meansarranged in general parallelism with said arm portion and pivotallyconnected at one end to said frame and at the other end to saidactuating member for swinging the latter, link means pivotally connectedat one end to said actuating means; said double acting fluid tiltcylinder means being longer than said link means, quick attachment meanspivotally connected to said link means and to said lift arm downwardlyextending portions, said quick attachment means also pivotally attachedto said bucket brackets, said upper attaching bucket brackets having anopen slot connection with said quick attachment means, and lift cylindermeans connected between said vehicle frame and said parallel linkassembly for vertically positioning the latter; a fluid control circuitincluding said tilt cylinder means and said lift cylinder means, saidtilt cylinder means including a pair of cylinder and piston units, firstconduit means connecting the rod end of said cylinders in fluidcommunication with one another, second conduit means connecting the headend of said cylinders in fluid communication with one another, a controlvalve between said first conduit means and said second conduit means forcausing selective pressurization of said rod ends and head ends of saidcylinders to cause actuation of said tilt cylinder means to thereby tiltsaid bucket through said actuating member and said link means, and afluid pressure relief valve in said control circuit and in communicationwith said second circuit means for dumping fluid pressure from the headend of said tilt cylinder means over a predetermined maximum when saidbucket is tilted to a predetermined position by said tilt cylinder meansand said bucket is being raised.
 2. The loader vehicle set forth inclaim 1 further characterized in that said open slot connectioncompriSes generally downwardly facing open ended slots in said upperbucket brackets, and said quick attachment means has bushings forinsertion in said slots for pivotal mounting of said attachment means insaid slots.